Introduction

The Temple University -Environmental Health and Radiation Safety (EHRS)  has developed a mercury thermometer recycling program to help eliminate mercury and its associated health and environmental hazards. The USEPA has identified mercury as one of their waste minimization priority chemicals, making the reduction of mercury a priority. The reduction in use of mercury is not only a U.S. priority, but is also an international priority. Other benefits include a reduction in costs associated with the cleanup and disposal of mercury and contaminated equipment, and less down time in research and teaching labs as spills are cleaned up.

How does the exchange program work?

The EHRS will provide a one-for-one exchange of mercury thermometers for select non-mercury thermometers. The non-mercury thermometers meet accuracy standards established by the National Institute of Standards and Technology (NIST). A mercury thermometer exchange request form that indicates the number of thermometers for pick up and the selected replacement thermometers are submitted to EHRS. EHRS will deliver the non-mercury thermometer to you and your mercury thermometers are picked up and returned to EHRS where they are packed and shipped for recycling. You or your department will not be billed for exchanging intact mercury thermometers

Facts about Non-Mercury Thermometers

Thermometer Storage and Fluid Separation

The science and development of non-mercury thermometers have made great improvements over the past few years. Blue spirit thermometers contain non-toxic isoamyl benzoate and dye. These thermometers can be stored horizontally; their separation rate is equal to or better than mercury thermometers. The red spirit thermometers that contain pentane or xylene and dye (-100° to 50°C and –50° to 50°C) should be stored vertically to reduce the chances of separation.

Temperature Ranges and Limits

There are non-mercury thermometers with temperature and accuracy ranges equal to most mercury thermometers. An exception is on the high end of the temperature scale. Until recently 260° C was the typical limit for non-mercury thermometers. A new Brown-Spirit thermometer has a maximum range greater than 300° C but the accuracy limit can be ± 5°C at high temperatures. If scientific procedures cannot be performed with non-mercury thermometers, Teflon coated mercury thermometers should be used. The Teflon coating will help to reduce releases of mercury should a thermometer be broken.

Scale Divisions and Accuracy Limits

Non-mercury thermometers have scale divisions equal to mercury thermometers. Most range from 0.5° to 1° C. Accuracy limits for non-mercury thermometers below 150° C are also compatible with mercury thermometers; accuracy is typically ± 1° - 2° C. For thermometers that have a high range of 260° C, accuracy below 100° C is ± 1°-2° C for both mercury and non-mercury thermometers. Above 100° C mercury thermometers have an accuracy range of ± 1.5° C, while non-mercury have an accuracy limit of ± 3° C.

National Institute of Standards and Technology

All of the non-mercury thermometers listed meet NIST standards.

Cleanup and Disposal

The non-mercury thermometers are non-toxic and environmentally safe. The broken glass should be placed in a sharps container to prevent injury. The remaining liquid can be cleaned up with soap and water.

Tips on Thermometer Selection and Use

Understanding the different classifications of thermometers and how to use them is essential for accurate temperature measurements. The following information is provided to help promote accuracy and repeatability.

Total Immersion Verses Partial Immersion Thermometers

Total immersion thermometers indicate the actual temperature when the bulb and the entire liquid column are exposed to the temperature being measured. To permit reading, typically one inch or less of the liquid column should be exposed. These thermometers can also be totally submerged in liquid or placed in a freezer.

Partial immersion thermometers indicate the actual temperature when a specified portion of the stem is exposed to the temperature being measured. A partial immersion thermometer will usually have an inscription stating the required depth or a ring inscribed on the stem, which indicates the depth.

Note: total immersion thermometers can be used as partial immersion if correction factors are known and used to calculate the temperature.

Exchange Procedures

1. Collect your mercury thermometers and determine which thermometers you would like to replace and which thermometers you no longer need.
2. Go to the replacement thermometers section and select the compatible replacement thermometers to find a replacement. For thermometers that do not have compatible non-mercury replacements, select Teflon coated thermometers listed on the Fisher Scientific website.
3. Go to the Mercury Thermometer Exchange Form and fill in the requested information.
4. Submit the completed form(s) electronically to EHRS at [click-for-email] or fax to 215-707-1600
5. Upon receipt, a representative of EHRS will come and complete the exchange.

Replacement Thermometers

The following non-mercury replacement thermometers are currently available from EHRS.

For more information and further product information, visit Fisher Scientific webpage

Related Information

Contact EHRS

Phone: 2-2520 or 215-707-2520 (off campus)